ap stats chapter 5

∩

intersection, and

∪

union, or

|

A given B

sample space

the list of all possible outcomes for some random process

event

any collection of outcomes from some random process

probability of equally likely outcomes

P(A) = (number of outcomes in event A) ÷ (total number of outcomes in sample space)

complement

P(A^c) = 1 - P(A)

the likelihood an event does not occur

mutually exclusive/disjoint

P(A or B) = P(A) + P(B)

when two events have no outcomes in common and so can never occur together

valid probability model

all probabilities are between 0 and 1 and add up to 1

general addition rule for two events

P(A or B) = P(A) + P(B) - P(A and B)

venn diagram

one or more circles surrounded by a rectangle. each circle represents an event. the region inside the rectangle represents the sample space of the random process.

intersection of events

the outcomes that two events have in common

union of events

all the outcomes of either event

conditional probability

P(A | B) = P(A and B)/P(B)

general multiplication rule

P(A and B) = P(A) * P(B | A) = P(B) * P(A | B)

independent events

P(A and B) = P(A) P(B)

P(A | B) = P(A)